Re: [R] DIF

2014-12-11 Thread munevver kaya
Thank you so much Phil, I will try that. Best On Wed, Dec 10, 2014 at 9:42 PM, Phil Chalmers wrote: > As well, the mirt package contains a function for DIF using likelihood > ratio tests via multiple-group estimation methods (the multiple group > estimation generally goes beyond simply testing f

Re: [R] DIF

2014-12-10 Thread Phil Chalmers
As well, the mirt package contains a function for DIF using likelihood ratio tests via multiple-group estimation methods (the multiple group estimation generally goes beyond simply testing for DIF), as well Wald tests if the information matrix was computed. Hope that helps. Phil On Wednesday,

Re: [R] DIF

2014-12-10 Thread munevver kaya
Thanks, Achim and Richard, I will take into consideration your solutions. Best, On Tue, Dec 9, 2014 at 11:36 PM, Achim Zeileis wrote: > On Tue, 9 Dec 2014, Richard M. Heiberger wrote: > > I recommend the likert() function in the HH package. >> >> install.packages("HH") >> library(HH) >> ?likert

Re: [R] DIF

2014-12-09 Thread Achim Zeileis
On Tue, 9 Dec 2014, Richard M. Heiberger wrote: I recommend the likert() function in the HH package. install.packages("HH") library(HH) ?likert I think this only visualizes the polytomous items but provides no formal inference for IRT modeling and DIF testing. For fitting polytomous IRT mo

Re: [R] DIF

2014-12-09 Thread Richard M. Heiberger
I recommend the likert() function in the HH package. install.packages("HH") library(HH) ?likert On Tue, Dec 9, 2014 at 3:22 AM, munevver kaya wrote: > Hello, > I will analyze polytomous differential item functioning for IRT. I have a > Likert type scale. For example, I want to analyze items in

[R] DIF

2014-12-09 Thread munevver kaya
Hello, I will analyze polytomous differential item functioning for IRT. I have a Likert type scale. For example, I want to analyze items in term of gender. Is lordifsufficient for this or are there any other packages in R programme? Best Regards, [[alternative HTML version deleted]] _

[R] DIF Analysis starting from a gpcm class object

2010-07-21 Thread Dr. Federico Andreis
Dear useRs, does any of you have suggestions on how to conduct a proper DIF analysis starting from a model of class gpcm (from the wonderful package ltm by prof. Rizopoulos)? difR will handle only dichotomous items, and I have a mix of dicho- and polytomous ones (that's why I chose the partial